The 335i is really the first non-///M 3-Series model that substantially widened the power/acceleration gap in the lineup. Prior to that the 325i/330i, 323i/328i, etc. were usually no more than a second apart either in the 0-60 race.

Given that, the N20 328i closes the gap somewhat but I fail to see how it makes the 335i irrelevant in any way. There is still lots of headroom in the N55 powertrain and it's very likely power will be increased by 20 hp or more in the near future. Others have also already pointed out that real-world 5-60 times, passing times and acceleration at higher speeds are dramatically different - the stock N55 still has a 60 hp advantage. Plus there's the sound and feel of the inline-6 that many people still want in a higher spec trim level than the 328i.

+1. Also, bear in mind that we are looking at BMW posted performance numbers for the 335, which in the E9X past were pretty understated. Doesn't InsideLine have a 4.9 second test on an N54 335?